The narrative is becoming all too familiar: A severe heat wave builds and, days later, people die. Now, legislators, scientists and a think tank are convening to better adapt to the most lethal weather phenomenon — by categorizing and naming it in major U.S. cities.

In January, California Insurance Commissioner Ricardo Lara and other delegates will formally introduce legislation to rate and name heat waves in Los Angeles — potentially establishing the nation’s first ranking system for such occurrences. The categorization would help communities take measures to reduce the number of heat-related fatalities.
(The Washington Post)

Heat waves have a particularly impact in Southern California, where they have become more frequent, intense and longer-lasting over the past five decades. Los Angeles is predicted by 2050 to experience an average of 22 extreme heat days annually — up from six days in the period from 1980 to 2000.

Los Angeles is one of six pilot locations in which the Arsht-Rockefeller Center is working. The others are Kansas City, Milwaukee and Miami-Dade County; and Athens and Seville, Spain. The center aims to improve communication and public recognition of heat-wave threats. In August 2020, the center formed the Extreme Heat Resilience Alliance, a group of emergency-response organizations, researchers, cities and nonprofit entities addressing the dangers of urban heat.

The concept is similar to the rating of hurricanes, but this ranking system would instead categorize heat waves on the basis of projected health outcomes rather than meteorology.

“This is, if not the only one, at least one of the very few meteorological warning systems that is based on the outcome,” said Larry Kalkstein, chief science adviser to the Arsht-Rockefeller Center. “That is, how many people are going to die rather than saying it’s going to be 105 degrees.”

Kalkstein and his team are creating three heat-wave categories to use in major U.S. cities. category 1 would indicate a relatively low number of expected deaths, perhaps a zero to 10 percent increase in daily mortality. Category 3 would indicate a larger potential increase in the number of deaths — such as occurred in the Pacific Northwest heat wave in June.

Each category would be tied to specific actions that can help alleviate the effects of the extreme heat. For instance, a category 3 designation could trigger the opening of municipal swimming pools and air-conditioned shelters, and even door-to-door checks on the elderly and other vulnerable members of the community. Local utilities could be prevented from cutting off air conditioning or power for nonpayment during intense heat events. Other protections could include altering the schedules of outdoor workers.